package com.yxp.offer;

import com.yxp.util.TreeNode;

/**
 * @author      : yang.xp
 * @date        : 2021/8/31 9:42
 * @description : 剑指 Offer 68 - II. 二叉树的最近公共祖先
 *
 * 给定一个二叉树, 找到该树中两个指定节点的最近公共祖先。(不是搜索树)
 */
public class Problem68_2 {

    public TreeNode lowestCommonAncestor(TreeNode root, TreeNode p, TreeNode q) {
        if(root == null || root == p || root == q)
            return root;

        TreeNode left = lowestCommonAncestor(root.left, p, q);
        TreeNode right = lowestCommonAncestor(root.right, p, q);

        if(left != null && right != null)
            return root;

        return left != null ? left : right;
    }
}
